QCD Corrections in two-Higgs-doublet extensions of the Standard Model with Minimal Flavor Violation
Abstract
We present the QCD corrections to Rb and to the Delta B=1 effective Hamiltonian in models with a second Higgs field that couples to the quarks respecting the criterion of Minimal Flavor Violation, thus belonging either to the (1,2)1/2 or to the (8,2)1/2 representation of SU(3)xSU(2)xU(1). After the inclusion of the QCD corrections, the prediction for Rb becomes practically insensitive to the choice of renormalization scheme for the top mass, which for the type-I and type-II models translates in a more robust lower bound on tan(beta). The QCD-corrected determinations of Rb and BR(B->Xs gamma) are used to discuss the constraints on the couplings of a (colored) charged Higgs boson to top and bottom quarks.
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